The present invention relates to an electronic flash device for a camera for automatically controlling the quantity of flash light emitted, according to the measurement of the quantity of the light reflected from a photographic object, and more particularly to an electronic flash device adapted to set information such as the sensitivity value of the film used in the camera and the aperture value to be set for the camera, when photographing, for the purpose of automatically controlling the quantity of flash light to be emitted, according to the measurement of the quantity of light reflected from a photographic object.
2. Description of the Prior Art
Hitherto, for setting for an electronic flash device information such as the sensitivity value of the film to be used in the camera and the aperture value to be set for the camera, when photographing, there has been provided a diaphragm in front of a light receiving portion used for measuring the light reflected from an object, wherein the aperture of the diaphragm is adjusted for this purpose. This, however, leads to difficulties and problems in the arrangement of the diaphragm and its adjusting mechanism. On the other hand, in the case of a so called "bouncing light photography" wherein flash light is emitted to objects other than the photographic object, such as for instance, to a ceiling, and then the light reflected therefrom is used for indirect illumination of a photographic object, since the light receiving portion which faces in the same direction as that of the light emitted is not directed toward the photographic object, there should be provided another separate light receiving portion for receiving the light from a photographic object. In the above case, there arises additional difficulties in providing an additional diaphragm and its adjusting mechanism for this separate light receiving portion. This in turn results in the necessity to increase the size of the aforesaid separate light receiving portion.
However, it is known that for simplifying the procedure for setting the aforesaid sensitivity value and aperture value for an electronic flash device, the aforesaid diaphragm adjusting mechanism is controlled in cooperation with the manipulation of a calculating means for an electronic flash device. However, this renders the cooperating or interlocking mechanism complicated or even impossible, when the aforesaid separate light receiving portion is used.